The invention relates to a method for identifying the angular position of a rotating object, such as a rotating shaft in the field of vehicle engineering.
In many areas of engineering, the problem arises of determining the angular position of an object rotating about an axis of rotation as accurately as possible. One widely used method in this regard involves providing the rotating object with a suitable encoding pattern which is scanned by means of a sensor so as to obtain information about the angular position of the rotating object. The encoding pattern, which is a sequence of binary symbols, is usually detected by the sensor contactlessly, for example when using a magnetic encoding pattern and a magneto-sensitive sensor.
A “Predictive Decision Feedback Equalizer” (pDFE) may be used in order to regenerate the encoding pattern of the rotating object from a measurement signal and to eliminate intersymbol interferences which are present in the measurement signal, the encoding pattern being regarded as a sequence of binary symbols.
For this purpose an output signal is supplied to a plurality of (e.g. digital) filters and the filtered signals are superposed with a sensor signal. The output signal is thus fed back to the sensor signal. The filter characteristic and hence the filter coefficients of the aforementioned filters can be predetermined constants or else can be adaptively adjusted in order to react to changes in the sensor arrangement.
For these and other reasons, there is a need for the present invention.